Search found 13 matches

by parrst
Mar 25 2020 7:59am
Forum: Battery Technology
Topic: building my first battery
Replies: 31
Views: 865

Re: building my first battery

Thank you for your help. Still having a hard time finding a BMS that is 20 amps 4S You do realize that 25A, 30A, 80A and higher are fine right? Looking not just on eBay and Amazon but Banggood and AliExpress? Searched for the threads I mentioned not just on the marine forums but Endless-Sphere and ...
by parrst
Mar 24 2020 10:23pm
Forum: Battery Technology
Topic: building my first battery
Replies: 31
Views: 865

Re: building my first battery

That **is** its spec for load ampacity. If you trust it, think it will also work with your load **types** then go for it! And let us know how it works of course. Thank you for your help. Still having a hard time finding a BMS that is 20 amps 4S. So if you happen to stumble on any, post a link. It s...
by parrst
Mar 24 2020 5:01pm
Forum: Battery Technology
Topic: building my first battery
Replies: 31
Views: 865

Re: building my first battery

I had not raised the issue of the wiring. >> what is the ampacity limit for the load terminals of your SC? Max charge current and max load current 20A. I have never seen a spec for acpicity. I may be new to building batteries but I am no stranger to electrical or electronic work. If the SC says it ...
by parrst
Mar 24 2020 2:19pm
Forum: Battery Technology
Topic: building my first battery
Replies: 31
Views: 865

Re: building my first battery

john61ct wrote:
Mar 24 2020 1:06pm
LMGTFY https://lmgtfy.com/?q=ampacity
I'm using 10 gage wire and round trip runs of about a foot or less.
by parrst
Mar 24 2020 1:01pm
Forum: Battery Technology
Topic: building my first battery
Replies: 31
Views: 865

Re: building my first battery

OK, but what is the ampacity limit for the load terminals of your SC? And do they state that all load types (e.g. resistive vs inductive) are supported? Best IMO to look at it as functionality, shared across simple robust OTS devices. As stated for "a BMS" brand, Chargery is one joey and others rec...
by parrst
Mar 24 2020 12:55pm
Forum: Battery Technology
Topic: building my first battery
Replies: 31
Views: 865

Re: building my first battery

Do balance the parallel groups to same voltage before assembly or before installing BMS. The bms will help keep a balance pack balance. I have three voltpheaks lifepo4 single cell charger @ 3.6v at 2amp. I haven't seen them in a while but someone must sell something like. Get a piece of paper and w...
by parrst
Mar 24 2020 12:23pm
Forum: Battery Technology
Topic: building my first battery
Replies: 31
Views: 865

Re: building my first battery

If you're talking about running all your loads through a SC, again good luck. Most are pretty fussy about the type of load they will support and are rated at very low power. Just use an adjustable BMS of enough ampacity, or even a standalone LVC. A SC is for charging from panels. My use is pretty l...
by parrst
Mar 24 2020 7:40am
Forum: Battery Technology
Topic: building my first battery
Replies: 31
Views: 865

Re: building my first battery

You can put two sightly different capacity cells in parallel they will act as one cell. The series set should all have same capacity if possible. So if you test all cells and write down info on each cell. Number them. So after finding out capacity match the headways and no name and match capacity.....
by parrst
Mar 23 2020 11:13pm
Forum: Battery Technology
Topic: building my first battery
Replies: 31
Views: 865

Re: building my first battery

There are hundreds of BMS, so many variables especially longevity / reliability, I just don't reco them. jonyjoe303 will reco the Chargery he uses, not expensive. If you do use a BMS for LVC, then you won't need to do whatever you were thinking with the SC, personally can't see how that would work....
by parrst
Mar 23 2020 11:08pm
Forum: Battery Technology
Topic: building my first battery
Replies: 31
Views: 865

Re: building my first battery

999zip999 wrote:
Mar 23 2020 9:22pm
Are they the screw-top version ?
yes.
by parrst
Mar 23 2020 8:57pm
Forum: Battery Technology
Topic: building my first battery
Replies: 31
Views: 865

Re: building my first battery

John, where do I find a decent BMS? My max current draw is only going to be 20 or 30 amps at most, and most of the time much lower, 5 or so jumping to 10 - 18 at most when I transmit and THAT is if I use for my big radio. I do also plan to use this for my CPAP when I camp and it can draw 3 - 3.5 amp...
by parrst
Mar 23 2020 8:48pm
Forum: Battery Technology
Topic: building my first battery
Replies: 31
Views: 865

Re: building my first battery

4 are headway the other 4 were supposed to be, but I think they may be knockoffs or "comparable", they are the slightly less capacity cells. I plan to use a solar charger/controller so that I can cut the use at 12 volts. Most of the BMSs I found have a cuttoff at 2V +-.1. That is WAY lower than I wa...
by parrst
Mar 23 2020 5:44pm
Forum: Battery Technology
Topic: building my first battery
Replies: 31
Views: 865

building my first battery

First off, I must admit I am not making a bike, rather a battery system for a ham radio portable kit. I am using LEFPO4 batteries at 15AH each. I am building an 8 cell $S battery. I have two questions. First question; is it best to build the battery with 4 sets (in series) of 2 cells (in parallel) a...